IFC (Industry Foundation Classes) is an international standard developed by buildingSMART for the building model data exchanging. It is a class library for Architecture, Engineering and Construction (AEC) objects, such as a wall or a window. IFC is written by EXPRESS of STEP. It takes the object-oriented approach, in which data are organized into a hierarchy of classes.

As IFC is non-proprietary and available globally to AEC/FM software developers, it enables interoperability among AEC/FM software applications, which means the end users in AEC/FM area can share the model data by IFCs. This helps to make interoperability a reality for AEC firms, building owners and authorities that use IFC-compliant software.